Adaptive cruise control following distance

I find it works just fine on setting #2 and gives me the 2 sec. distance. Yes, morons will cut in. Would you rather hit the guy in front or allow the morons to do their thing? We have fault insurance here, and hitting someone in the rear is 100% your fault.
Maybe it's not the thing on the California freeways.

 

Does the Owner's Manual specify what the following distance is of each setting? We don't have that feature in our Prius, but we do in our Fusion Hybrid. In the Fusion Hybrid the longest following distance is about 2.7 seconds at 62 MPH according to the OM. On the freeway I don't like to follow any closer for safety reasons. In Driver's Ed we were taught a 3 second following distance minimum. Our weather is so crazy in MN that I usually try to keep a 3+ second following distance on dry roads and even more when the weather is bad.

 

At 15' four car lengths are 60'. At 60mph the car travels 88 feet per second. When something happens can a driver stop or avoid the vehicle in front within 0.68 second? Many people just don't maintain a safe following distance.

I agree that it accelerates too quickly and I feel it brakes too sharply.

 

Exactly the opposite. The follow distance even on the longest setting is too far for safe distancing at higher speeds. A number of roads in my area have safe following markings on them (large dots) and without fail my Prius 2013 doesn't allow enough distance at speeds over 55 mph.

If you're using the medium or close distance you're looking for trouble.

 

I typically use it on medium, but will switch it to short when somebody cuts in, or to the far setting if I'm approaching a slower-moving car and want it to slow down more gradually. When accelerating, I'll switch it to the longer settings just as it starts accelerating hard, so that keeps it from accelerating too quickly for my taste.

There are many people in CA that will cut in even on the short setting; but I avoid most of them by not driving during rush hour. At other times, it's a little less crowded, and I don't have as many problems with people cutting in.

 

I always use the default 3 bar and follow behind a big rig. Sometimes 2 bars. No one wants to cut behind a big rig anyway. I find that the closer the following distance, the more aggressive braking and acceleration.

 

We really like it. It's much more comfortable than the Prius.We would never take the Prius on a long trip because the comfort level isn't there. The interior is all hard plastic in the Prius and the seats are uncomfortable. The Fusion interior is all soft touch materials and the seats are comfortable even after spending 16 hours in them in one day on a road trip.

We average 40 MPG in the winter & 50-55 MPG in the summer in the Fusion. The Prius averages about 42 MPG in the winter and 50-55 MPG in the summer. The Prius doesn't seem to have a huge drop in MPG on the freeway compared to in the city. The FFH drops more at freeway speeds. But we've gotten 44-45 MPG on 4500 mile road trips in the Fusion, so it still does quite well at 65+ MPH. All those MPG numbers are based on the pump and not the dash display.

 

Some rebuttal, regarding "cutting in":

HOWTO singlehandedly erase traffic jams by driving slow - Boing Boing

SCIENCE HOBBYIST: Traffic Waves, physics for bored commuters

(for sure read the comments following the above, they cover the spectrum)

 

I have been using the 1 bar, but I think it brakes too hard. This is in multi lane Florida 55+ stoplight driving. I If I was on an actual highway, I think I would use the 3 bar.

I am very good at judging closing speeds and the speeds of drivers around me so I usually know when they car in front of me should be braking or not.

 

I've probably driven 45K with the DCC on our 2011 and usually use the closest setting - particularly in heavy traffic. I've found that the system reacts (and brakes) much faster than I can when some a-hole cuts in (we have plenty of experience with that in Chicago rush-hour traffic). Also, keep in mind, that the PCS is also active and definitely will apply heavy braking if a collision is eminent. I've had that happen a couple of times (around Chicago, of course )

I often use the middle setting when on winding country roads, and poor road conditions. Only use the longest setting when I am in no rush and sticking strictly to the right lane.

Regarding accelerating too fast: Yes it does (a bit) - but (at least in the 2011) if YOU depress the gas pedal to get the acceleration you want, that overrides the system.

 

I use the shortest one because otherwise other cars will just cut in front of me. Not surprisingly since this is L.A. traffic we're talking about.

 

Funny but I went back to my owners manual and I MISSED the note that the follow distance changes based on the car speed. I'm glad I looked. In that case you are probably right that Toyota is using recommended follow distances for safe follow.

Always glad to learn something new and admit if I've been wrong or mistaken.

Here's the relevant section from my 2013 Prius manual:

Vehicle-to-vehicle distance settings. Select a distance from the table below. Note that the distances shown correspond to a vehicle speed of 50 mph (80 km/h). Vehicle-to-vehicle distance increases/decreases in accordance with vehicle speed.

Distance options


Vehicle-to-vehicle distance

Long


Approximately 160 ft. (50 m)

Medium


Approximately 130 ft. (40 m)

Short


Approximately 100 ft. (30 m)